Electrochemical double-layer capacitors, also known as double-layer capacitors (DLC) or supercapacitors or Ultracapacitors can generally be described as energy storage devices that can combine the higher energy storage potential of batteries with nearly the high energy transfer rate or high charging/discharging capabilities of conventional dielectric capacitors. Early versions of DLCs were used as motor startup capacitors for large engines in tanks and submarines. More recently, DLCs have been developed for use in smaller items such as PC Cards, flash photography devices in digital cameras, flashlights, portable media players, energy storage in electric vehicles for regenerative braking/accelerating and the like.